* {
	margin: 0;
	padding: 0;
}
.main {
	position: absolute;
	width: 400px;
	height: 200px;
	background-color: #ccc;
	top: 50%;
	margin-top: -100px;
	left: 50%;
	margin-left: -200px;
}
.left-top-area {
	width: 50px;
	height: 50px;
	border-radius: 0 0 50px 0;
	position: absolute;
	background-color: #FC0;
}
.right-bottom-area {
	width: 50px;
	height: 50px;
	border-radius: 50px 0 0 0;
	position: absolute;
	background-color: #FC0;
	right: 0;
	bottom: 0;
}